I have finally made my own stir plate. I used the instructions from this website
. I tested it out and it works well. My only concern is that the fan doesn't seem to turn as fast as I like. When I stir some water, I get a small dimple in the middle but no vortex all the way down. I'm wondering if it's the power supply. I'm using a 5V plug. If I used a 12V plug would it burn up my fan? Here's a picture of the tech specs.